Consider the Hyundai Venue HX5+ with the 1.2 petrol manual. It fits comfortably in your budget, has a spacious and comfortable back seat and gets features like rear AC vents and a rear window sunshade. If you'd like, and even a roomier rear seat, the Kia Syros is a great choice, but it only comes with the turbo petrol, which will be slightly less fuel efficient.

Stretching your budget to Rs 14 lakh gets you options from the midsize SUV segment. Among these, the Kia Seltos and the Honda Elevate 1.5 petrol manuals are strong choices. The will be roomier than the Venue, with more comfortable rear seats, and will be relatively fuel efficient in the city. However, your budget will get you the lower-end trims, which may lack some features. Alternatively, you could consider the Honda City.

Overall, for your budget, the Venue is a great fit.

Your i20 Magna deal at Rs. 7.25 lakh on-road is tempting. It is very comfortable, has a smooth light clutch, and the cabin is spacious for family use. Hyundai service reach helps if you are unsure about yearly running. But the Magna is fairly bare-bones and doesn't come with a screen, so what you are referring to is probably a dealer fitment. The 1.2 petrol is refined but can feel a bit lazy for quick highway passes. Expect mid-teen kpl in mixed use, not class-best. Also, check that you are getting recent stock and that the infotainment comes with a warranty. If you want a more fuel-efficient choice, then consider the Maruti Suzuki Swift VXi.

For your requirements, the Punch offers the right combination of comfort, ease of use and practicality. The higher seating position makes getting in and out easier than in a hatchback, while the 90-degree opening doors are particularly helpful for those with knee or hip issues. Its suspension is well-suited to broken city roads, and the generous ground clearance provides added confidence during the monsoon and on waterlogged streets.

The automatic gearbox removes the need to operate a clutch in slow-moving traffic, which can make daily driving considerably less tiring. It is also compact enough to be easy to manoeuvre and park in the city.

The Hyundai Exter AMT is another option worth considering, but the Punch feels more substantial and offers better ride comfort on poor road surfaces.

There is no reason to avoid either a petrol or a diesel car purely because of future fuel-blending plans.

Just as modern petrol cars are being engineered to handle higher ethanol blends, any future diesel blend regulations will be accompanied by corresponding changes from vehicle manufacturers. If isobutanol blending is introduced, it will be done in a controlled manner, and vehicles sold in the market will be calibrated accordingly. There is currently no evidence to suggest that such blends would cause adverse effects on modern diesel engines when used within the prescribed limits.

The more important question is whether a diesel suits your usage pattern. If your running is high and includes regular highway trips, the Altroz Diesel remains a compelling option. However, if your usage is predominantly urban, the Honda Amaze CVT is still the more sensible choice. It offers a smoother driving experience, lower complexity and none of the DPF-related concerns associated with modern diesel engines.

Considering the features you've listed, namely ADAS, a 360-degree camera and ventilated seats, the shortlist effectively narrows down to the Hyundai Verna and Kia Seltos.

In fact, the car that would normally be recommended to an enthusiast is the Volkswagen Virtus 1.5 TSI DSG. It remains one of the most rewarding cars to drive in this segment, and there are attractive discounts available at the moment as a facelift is expected in the near future. However, it misses out on some of the features that are clearly important to you.

Between the Verna and Seltos, the nod goes to the Seltos. It is the newer product, feels more premium inside, offers greater practicality and has a more spacious cabin. It also benefits from the same excellent 1.5-litre turbo-petrol and dual-clutch automatic combination as the Verna, so you are not sacrificing performance. Over the long term, it is also likely to hold its value better.

For your usage as a second car that will spend most of its life in the city, the Tata Punch EV Long Range would actually be the first choice. It is compact, easy to manoeuvre, offers more than enough range for daily duties and is based on a dedicated EV architecture rather than an ICE conversion. It also gets a modern feature set and feels purpose-built as an electric vehicle.

If you want something larger and more spacious, the MG Windsor EV is the alternative to consider. It offers exceptional cabin space and comfort, and feels like a segment-above product for the money.

As for the Mahindra XUV 3XO EV, it carries over the 39.4kWh battery pack and electric motor from the XUV400, rather than using the newer INGLO-based technology seen on the BE 6 and XEV 9e. So while it benefits from the new 3XO interior and feature set, the underlying EV hardware is not all-new.

The Kia Carens Clavis is probably the closest match to your requirements at this price point. The challenge is that the combination of features you're looking for is typically found on higher variants. In the Clavis, you'll need to move up the variant ladder to get most of these features, and that means accepting the sunroof as part of the package.

As for the petrol versus diesel debate, your usage pattern actually favours petrol. Your monthly running is relatively low, and the frequent 3km city trips are not ideal for modern diesel engines. The occasional 500km highway journeys are easily handled by a petrol automatic. Ethanol blending should not be a major concern either, as modern petrol cars are engineered to run on the fuels currently available and planned for India.

The Honda Amaze CVT would be the recommendation here. For a beginner driver with predominantly city usage, the Amaze's CVT automatic is a major advantage. It is smoother, more refined and easier to drive in stop-start traffic than the AMT offered in the Exter. The sedan also offers a more comfortable ride, a larger boot and a mature driving experience that will remain satisfying even as your driving skills improve.

The Hyundai Exter counters with its higher seating position, which some new drivers find reassuring, along with better ground clearance for rough roads and speed breakers. However, its AMT gearbox is not as seamless as the Honda's CVT.

With around 70 percent highway driving, a diesel SUV is still very well suited to your requirements. In fact, your usage should normally be sufficient to keep the DPF healthy, provided the vehicle is regularly driven at sustained speeds. The fact that the DPF warning light is appearing after relatively short city runs suggests there could be an underlying issue that needs investigation rather than this being purely a usage-related problem.

Before taking the significant financial hit of selling a 3.5-year-old vehicle, it would be worth getting the car thoroughly inspected by Hyundai and escalating the matter if necessary. A healthy diesel vehicle should not be causing repeated DPF concerns with your mix of highway and city driving.

As for the alternatives, the naturally aspirated 1.5-litre petrol engines in the Creta and Seltos are smooth, refined and hassle-free, but they will feel less effortless on the highway and will not match the diesel's fuel efficiency. The Venue 1.2 petrol would be an even bigger step down in performance.

Go for the Hyundai Venue. It sits on the newer platform and has a 5-star Bharat NCAP rating. It also has the better back seat among the two, which helps on long trips with family, and the cabin feels a touch more airy. For highway-heavy use you could consider the 1.5 diesel which is refined and gives good real world mileage. 

The Sonet has the firmer suspension between the two; it isn't as absorbent as the Venue over rough roads, but feels a bit more planted on the highway. If you’re fixed on petrol within Rs. 12 lakh, the Venue is solid pick.